117
FXUS65 KPSR 210816
AFDPSR

Area Forecast Discussion
National Weather Service Phoenix AZ
116 AM MST Tue May 21 2024

.SYNOPSIS...
Typical dry late-May weather will persist through the remainder
of this week and this weekend, with near normal temperatures each
day as lower desert highs reach the nineties. Typical daily
breeziness in the afternoons can be expected. A weak disturbance
late this week will bring a slight enhancement to the winds and
cool temperatures slightly. By early next week temperatures will
warm to above normal as high pressure develops.

&&

.DISCUSSION...
Global ensemble models maintain strong agreement in the
persistence of a longwave trough pattern across the Western CONUS
through the remainder of this week and this weekend, with a few
embedded dry shortwave troughs, but no substantial weather impacts.
H5 heights are expected to remain around 576-580dm over the area
which is typical for this time of year. So, for the 6 days fairly
typical dry Spring weather is expected across the Desert
Southwest. This will include daily widespread Minor HeatRisk, with
afternoon lower desert high temperatures in the 90s, right at
seasonal normals, plenty of sun, and overnight lows in the 60s.
Typical afternoon breeziness can be expected, with most days
gusting into the 15-30 mph range across the southern deserts.
Slight enhancements to the wind are possible with passing
shortwaves. Currently, the strongest/deepest wave looks to impact
the region Friday and Saturday, with potential for stronger wind
gusts, including in excess of 35 mph in Southeast CA. Following
the shortwave late this week and this weekend, global ensembles
are strongly in favor of a high-amplitude ridge developing across
the Western CONUS heading into early next week, with H5 heights
climbing up to the 585-590dm range. This will lead to 100 degree
afternoon temperatures again and potentially the hottest
temperatures of the year so far.

&&

.AVIATION...Updated at 0530Z.

South-Central Arizona including KPHX, KIWA, KSDL, and KDVT:
Winds have substantially calmed across all the terminals, now
exhibiting speeds aob 6 kt. Some light, erratic behavior will be
possible through the next several hours before winds definitively
establish out of their typical E/SE drainage directions. Going
forward, wind directions will generally follow diurnal tendencies.
Expect southwest winds to establish by the afternoon across the
terminals with occasional gusts into the mid teens through early
tomorrow evening. Clear skies will prevail through the period,
aside from a thinly scattered deck to the SE based around 8-10 kft
lingering for another hour or so.

Southeast California/Southwest Arizona including KIPL and KBLH:
No aviation weather concerns will exist through the next 24 hours
under clear skies. Winds will lessen and turn out of the NW
overnight at KIPL and are expected to pick up again out of the W
tomorrow evening, but with speeds mostly aob 12 kt sustained and
gusts potentially into the low 20s. An extended period of light
wind speeds (aob 6 kt sustained) and variability can be
anticipated at KBLH after southerly winds subside tonight.

&&

.FIRE WEATHER...
Very typical mid/late May weather will prevail the remainder of the
week highlighted by seasonably warm temperatures, dry conditions,
and frequently breezy afternoon/early evenings. Minimum afternoon
humidity levels will mostly fall into the single digits with some
modest improvement into a 10-20% level towards the end of the week.
This will follow generally poor to fair overnight recovery of 20-
40%. Wind gusts 15-25 mph will be common through the week. A
slight enhancement is anticipated during the late-week timeframe
as a dry system moves through. Wind gusts with the late-week
system may increase up to 25-30 mph, to as high as 30-40 mph near
terrain features, and the Imperial Valley, resulting in an
elevated, to perhaps locally critical, fire danger.


&&

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&

$$

DISCUSSION...Benedict
AVIATION...Whittock
FIRE WEATHER...18/Benedict